Greg Hakim

Green's function solutions for the Sawyer--Eliassen equation are derived and compared for quasi-geostrophic and semi-geostrophic two-dimensional frontal dynamics in vertically bounded domains. The semi-geostrophic Green's functions provide a framework for understanding canonical frontal circulation patterns arising from interactions, or coupling, between upper- and lower-tropospheric jet--front systems. Previously documented conceptual models for these circulation patterns are reproduced by the solutions. A noteworthy finding is that vertical coupling produces a deep and narrow region of ascent when the upper- and lower-tropospheric point sources for the Green's functions share the same sign and absolute momentum surface.